Too Much TV May Have Deadly Toll

Each Hour of TV Daily Associated With an 18% Increased Risk of Death From Cardiovascular Disease

Jan 11, 2010 -- Watch out, couch potatoes! A new study says that every hour of TV you watch daily may increase your risk of early death from cardiovascular disease.

Australian researchers, reporting in Circulation: Journal of the American Heart Association, studied the lifestyle habits of 8,800 adults. They found that each hour spent watching television on a daily basis is associated with an 18% increased risk of death from cardiovascular disease.

They also say an hour a day spent in front of the tube is associated with:

Human Body Needs to Move

The human body evolved to move, not sit still for extended periods of time, says David Dunstan, PhD, lead author of the study and head of the Physical Activity Laboratory at the Baker IDI Heart and Diabetes Institute in Victoria, Australia. So sitting in front of a TV or a computer screen for too long poses serious risks to health, and to life, the researchers say.

“What has happened is that a lot of the normal activities of daily living that involved standing up and moving the muscles in the body have been converted to sitting,” Dunstan says in a news release. “Technological, social, and economic changes mean that people don’t move their muscles as much as they used to -- consequently the levels of energy expenditure as people go about their lives continue to shrink. For many people, on a daily basis, they simply shift from one chair to another, from the chair in the car to the chair in the office to the chair in front of the television.”

Dunstan and his team of researchers looked at 3,846 men and 4,954 women ages 25 and older to find out what happens to people who sit too much. They were asked about their TV viewing habits and were grouped into one of three categories: people who watched less than two hours of TV daily, those who watched between two and four hours of television daily, and those who spent more than four hours in front of the tube. The researchers excluded people with a history of cardiovascular disease, and the entire group was then followed for more than six years. During the study period, 284 of the people died, 125 from cancer and 87 because of cardiovascular disease.

Dunstan and his colleagues write that the link between cancer and TV viewing was only modest, but that there was a direct association between television time and elevated cardiovascular death, as well as death from all causes. This was true, they say, even after accounting for typical cardiovascular disease risk factors and other lifestyle practices.